1. Field of the Invention
This invention relates to a system for sounding an alarm and inhibiting the application of power to an automobile starter motor until the occurrence of a sequence of signals from sensors associated with the vehicle seat and the seat belt indicating that the seat belts are in proper condition for operation of the vehicle and to means for disabling the operation of this alarm and inhibiting system under certain special conditions.
2. Description of the Prior Art
The need for a system for preventing the operation of an automobile unless the occupants have fastened their seat belts is well recognized and present government regulations require that new cars sold in the future be equipped with such systems. Previous systems for this purpose have generally involved variations of one of several concepts. One class of such systems has utilized switches built into the buckles of seat belts and interconnected with the starter motor circuitry so as to inhibit starting of the vehicle if the buckle is not fastened. Another class of systems employs switches associated with retractors for the seat belts to assure that the seat belts are extended before the vehicle can be started. A variation on this concept utilizes pressure sensitive switches built into the seats of the vehicle so as to condition starting of the vehicle on the closure of only the seat belts associated with occupied seats.
These previously proposed systems have generally met with two problems in actual use. First, most of the systems heretofore disclosed have been relatively simple to disable if the driver did not want to fasten his seat belt each time he occupied the car. This might be done by permanently fastening the tongue of one section of the belt buckle to the other section of the belt and pushing them into a seat crevice or by forming a knot or other protuberance on a belt section so that it is permanently disposed in an extended condition from its retractor.
Another class of problems encountered by prior art systems is related to their creation of complications during unusual situations which occur in the operation of the vehicle. For example, a system which requires that the seat belt buckle be latched within a predetermined time period before the engine is started may constitute a nuisance or create a danger in situations where the engine stalls. Rather than just restarting of the vehicle, the driver may be required to unfasten his seat belt and then refasten it before he can start the car. On a busy road this delay may be hazardous.